Choose the correct preposition.

Internal combustion engines such as reciprocating internal combustion engines produce air pollution emissions, due to / for incomplete combustion of / from carbonaceous fuel. The main derivatives from / of the process are carbon dioxide CO 2, water and some soot — also called particulate matter (PM). The effects of / from inhaling particulate matter have been studied on / in humans and animals and include asthma, lung cancer, cardiovascular issues, and premature death. There are, however, some additional products of / for the combustion process that include nitrogen oxides and sulfur and some uncombusted hydrocarbons, depending on / in the operating conditions and the fuel-air ratio.

Not all of / from the fuel is completely consumed with / by the combustion process; a small amount off / of fuel is present after / before combustion, and some from / of it reacts to / for form oxygenates, such as formaldehyde or acetaldehyde, or hydrocarbons not originally present in / on the input fuel mixture. Incomplete combustion usually results for / from insufficient oxygen to achieve the perfect stoichiometric ratio. The flame is "quenched" with / by the relatively cool cylinder walls, leaving behind / in front of unreacted fuel that is expelled with / within the exhaust. When running at / near lower speeds, quenching is commonly observed in / on diesel (compression ignition) engines that run in / on natural gas.

 

Read the passage about gas turbine and open the brackets.

A gas turbine _______ (to call) a gas turbine because it _______ (to compress) a gas, usually air. There are three stages to a turbine: 1) air _______ (to draw) through a compressor where the temperature _______ (to rise) due to compression, 2) fuel _______ (to add) in the combuster, and 3) hot air _______ (to exhaust) through turbines blades which _______ (to rotate) a shaft _______ (to connect) to the compressor.

A gas turbine is a rotary machine similar in principle to a steam turbine and it ______ (to consist) of three main components: a compressor, a combustion chamber, and a turbine. The air, after _______ (to compress) in the compressor, _______ (to heat) by _______ (to burn) fuel in it. About ⅔ of the _______ (to heat) air, _______ (to combine) with the products of combustion, _______ (to expand) in a turbine, _______ (to produce) work output that _______ (to drive) the compressor. The rest (about ⅓) is available as useful work output.

The jet engine _______ (to take) a large volume of hot gas from a combustion process (typically a gas turbine, but rocket forms of jet propulsion often _______ (to use) solid or liquid propellants, and ramjet forms also lack the gas turbine) and _______ (to feed) it through a nozzle that _______ (to accelerate) the jet to high speed. As the jet _______ (to accelerate) through the nozzle, this _______ (to create) thrust and in turn _______ (to do) useful work.

 

LISTENING

11. Listen to the text about the turbine and tell what the text is about:

– modern application;

– history;

– development;

– advantages;

– manufacturing.

 

Listen to the text once more and insert the necessary word.

In 1831 William Avery and his friend were granted a patent for a _______ device very similar to one of those ancient Egyptian toys. Jets of steam, emitted from either end of a whirling propeller-like _______, drove it. By that time, Watt and others had already tried and failed at creating _______ steam-driven machines. And the French had just begun developing the water _______ Modern steam turbines don't work the same way as Avery's. They direct steam through a succession of _______. Each stage removes energy and reduces the steam _______. The _______ of those blades gets very complex.

In Avery’s turbine, steam flowed from the hub out through the _______ where it escaped as a driving jet. The tips approached the speed of _______ and, when one of Avery's cast iron rotors failed, its fragments tore through three floors of a building.

 

Answer the questions.

1. What are the sources of power now?

2. What is at the base of a dam?

3. How are turbines driven?

4. How do modern turbines work?

5. How did Avery’s turbine work?

6. What did Avery use to get power out at useful speeds?

7. What other devices did he invent?

8. Why was the turbine the natural mate to the generator?

9. Why is Parson considered to be the inventor of the turbines?

10. What are turbines used for?

 

SPEAKING